Add support for 'vulture' for Python

5 files changed, 209 insertions, 2 deletions

diff --git a/README.md b/README.md
index e11c54b2..a7ba2794 100644
--- a/README.md
+++ b/README.md
@@ -159,7 +159,7 @@ formatting.
 | proto | [protoc-gen-lint](https://github.com/ckaznocha/protoc-gen-lint) |
 | Pug | [pug-lint](https://github.com/pugjs/pug-lint) |
 | Puppet | [languageserver](https://github.com/lingua-pupuli/puppet-editor-services), [puppet](https://puppet.com), [puppet-lint](https://puppet-lint.com) |
-| Python | [autopep8](https://github.com/hhatto/autopep8), [black](https://github.com/ambv/black), [flake8](http://flake8.pycqa.org/en/latest/), [isort](https://github.com/timothycrosley/isort), [mypy](http://mypy-lang.org/), [prospector](http://github.com/landscapeio/prospector), [pycodestyle](https://github.com/PyCQA/pycodestyle), [pyls](https://github.com/palantir/python-language-server), [pyre](https://github.com/facebook/pyre-check), [pylint](https://www.pylint.org/) !!, [yapf](https://github.com/google/yapf) |
+| Python | [autopep8](https://github.com/hhatto/autopep8), [black](https://github.com/ambv/black), [flake8](http://flake8.pycqa.org/en/latest/), [isort](https://github.com/timothycrosley/isort), [mypy](http://mypy-lang.org/), [prospector](http://github.com/landscapeio/prospector), [pycodestyle](https://github.com/PyCQA/pycodestyle), [pyls](https://github.com/palantir/python-language-server), [pyre](https://github.com/facebook/pyre-check), [pylint](https://www.pylint.org/) !!, [vulture](https://github.com/jendrikseipp/vulture), [yapf](https://github.com/google/yapf) |
 | QML | [qmlfmt](https://github.com/jesperhh/qmlfmt), [qmllint](https://github.com/qt/qtdeclarative/tree/5.11/tools/qmllint) |
 | R | [lintr](https://github.com/jimhester/lintr) |
 | ReasonML | [merlin](https://github.com/the-lambda-church/merlin) see `:help ale-reasonml-ols` for configuration instructions, [ols](https://github.com/freebroccolo/ocaml-language-server), [refmt](https://github.com/reasonml/reason-cli) |
diff --git a/ale_linters/python/vulture.vim b/ale_linters/python/vulture.vim
new file mode 100644
index 00000000..bff7d623
--- /dev/null
+++ b/ale_linters/python/vulture.vim
@@ -0,0 +1,84 @@
+" Author: Yauheni Kirylau <actionless.loveless@gmail.com>
+" Description: vulture linting for python files
+
+call ale#Set('python_vulture_executable', 'vulture')
+call ale#Set('python_vulture_options', '')
+call ale#Set('python_vulture_use_global', get(g:, 'ale_use_global_executables', 0))
+call ale#Set('python_vulture_change_directory', 1)
+
+
+" The directory to change to before running vulture
+function! s:GetDir(buffer) abort
+    let l:project_root = ale#python#FindProjectRoot(a:buffer)
+
+    return !empty(l:project_root)
+    \   ? l:project_root
+    \   : expand('#' . a:buffer . ':p:h')
+endfunction
+
+
+function! ale_linters#python#vulture#GetExecutable(buffer) abort
+    return ale#python#FindExecutable(a:buffer, 'python_vulture', ['vulture'])
+endfunction
+
+
+function! ale_linters#python#vulture#GetCommand(buffer) abort
+    let l:change_dir = ale#Var(a:buffer, 'python_vulture_change_directory')
+    \   ? ale#path#CdString(s:GetDir(a:buffer))
+    \   : ''
+
+    let l:executable = ale_linters#python#vulture#GetExecutable(a:buffer)
+
+    let l:exec_args = l:executable =~? 'pipenv$'
+    \   ? ' run vulture'
+    \   : ''
+
+    let l:lint_dest = ale#Var(a:buffer, 'python_vulture_change_directory')
+    \   ? ' .'
+    \   : ' %s'
+
+    return l:change_dir
+    \   . ale#Escape(l:executable) . l:exec_args
+    \   . ' '
+    \   . ale#Var(a:buffer, 'python_vulture_options')
+    \   . l:lint_dest
+endfunction
+
+
+function! ale_linters#python#vulture#Handle(buffer, lines) abort
+    for l:line in a:lines[:10]
+        if match(l:line, '^Traceback') >= 0
+            return [{
+            \   'lnum': 1,
+            \   'text': 'An exception was thrown. See :ALEDetail',
+            \   'detail': join(a:lines, "\n"),
+            \}]
+        endif
+    endfor
+
+    " Matches patterns line the following:
+    let l:pattern = '\v^([a-zA-Z]?:?[^:]+):(\d+): (.*)$'
+    let l:output = []
+    let l:dir = s:GetDir(a:buffer)
+
+    for l:match in ale#util#GetMatches(a:lines, l:pattern)
+        let l:abspath = ale#path#GetAbsPath(l:dir, l:match[1])
+        let l:item = {
+        \   'filename': l:abspath,
+        \   'lnum': l:match[2] + 0,
+        \   'text': l:match[3],
+        \   'type': 'W',
+        \}
+        call add(l:output, l:item)
+    endfor
+
+    return l:output
+endfunction
+
+
+call ale#linter#Define('python', {
+\   'name': 'vulture',
+\   'executable_callback': 'ale_linters#python#vulture#GetExecutable',
+\   'command_callback': 'ale_linters#python#vulture#GetCommand',
+\   'callback': 'ale_linters#python#vulture#Handle',
+\})
diff --git a/doc/ale-python.txt b/doc/ale-python.txt
index e24ef1aa..093ea758 100644
--- a/doc/ale-python.txt
+++ b/doc/ale-python.txt
@@ -398,6 +398,36 @@ g:ale_python_pyre_use_global                     *g:ale_python_pyre_use_global*
 
 
 ===============================================================================
+vulture                                                    *ale-python-vulture*
+
+g:ale_python_vulture_change_directory   *g:ale_python_vulture_change_directory*
+                                        *b:ale_python_vulture_change_directory*
+  Type: |Number|
+  Default: `1`
+
+  If set to `1`, ALE will switch to the directory the Python file being
+  checked with `vulture` is in before checking it and check the whole project
+  directory instead of checking only the file opened in the current buffer.
+  This helps `vulture` to know the context and avoid false-negative results.
+
+
+g:ale_python_vulture_executable               *g:ale_python_vulture_executable*
+                                              *b:ale_python_vulture_executable*
+  Type: |String|
+  Default: `'vulture'`
+
+  See |ale-integrations-local-executables|
+
+
+g:ale_python_vulture_use_global               *g:ale_python_vulture_use_global*
+                                              *b:ale_python_vulture_use_global*
+  Type: |Number|
+  Default: `get(g:, 'ale_use_global_executables', 0)`
+
+  See |ale-integrations-local-executables|
+
+
+===============================================================================
 yapf                                                          *ale-python-yapf*
 
 g:ale_python_yapf_executable                     *g:ale_python_yapf_executable*
diff --git a/doc/ale.txt b/doc/ale.txt
index fdb2d0a6..24f57424 100644
--- a/doc/ale.txt
+++ b/doc/ale.txt
@@ -207,6 +207,7 @@ CONTENTS                                                         *ale-contents*
       pylint..............................|ale-python-pylint|
       pyls................................|ale-python-pyls|
       pyre................................|ale-python-pyre|
+      vulture.............................|ale-python-vulture|
       yapf................................|ale-python-yapf|
     qml...................................|ale-qml-options|
       qmlfmt..............................|ale-qml-qmlfmt|
@@ -399,7 +400,7 @@ Notes:
 * proto: `protoc-gen-lint`
 * Pug: `pug-lint`
 * Puppet: `languageserver`, `puppet`, `puppet-lint`
-* Python: `autopep8`, `black`, `flake8`, `isort`, `mypy`, `prospector`, `pycodestyle`, `pyls`, `pyre`, `pylint`!!, `yapf`
+* Python: `autopep8`, `black`, `flake8`, `isort`, `mypy`, `prospector`, `pycodestyle`, `pyls`, `pyre`, `pylint`!!, `vulture`, `yapf`
 * QML: `qmlfmt`, `qmllint`
 * R: `lintr`
 * ReasonML: `merlin`, `ols`, `refmt`
diff --git a/test/handler/test_vulture_handler.vader b/test/handler/test_vulture_handler.vader
new file mode 100644
index 00000000..c6bd7643
--- /dev/null
+++ b/test/handler/test_vulture_handler.vader
@@ -0,0 +1,92 @@
+Before:
+  runtime ale_linters/python/vulture.vim
+
+  call ale#test#SetDirectory('/testplugin/test/handler')
+
+After:
+  Restore
+
+  call ale#test#RestoreDirectory()
+  call ale#linter#Reset()
+
+  silent file something_else.py
+
+Execute(Basic vulture check with relative path in result should be handled):
+  call ale#test#SetFilename('something_else.py')
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 34,
+  \     'text': 'unused variable ''foo'' (60% confidence)',
+  \     'type': 'W',
+  \     'filename': ale#path#Simplify(g:dir . '/something_else.py'),
+  \   },
+  \ ],
+  \ ale_linters#python#vulture#Handle(bufnr(''), [
+  \   './something_else.py:34: unused variable ''foo'' (60% confidence)',
+  \ ])
+
+Execute(Basic vulture check with absolute path in result should be handled):
+  call ale#test#SetFilename('something_else.py')
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 34,
+  \     'text': 'unused variable ''foo'' (60% confidence)',
+  \     'type': 'W',
+  \     'filename': ale#path#Simplify(g:dir . '/something_else.py'),
+  \   },
+  \ ],
+  \ ale_linters#python#vulture#Handle(bufnr(''), [
+  \   ale#path#Simplify(g:dir . '/something_else.py') . ':34: unused variable ''foo'' (60% confidence)',
+  \ ])
+
+Execute(Vulture check for two files should be handled):
+  call ale#test#SetFilename('something_else.py')
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 34,
+  \     'text': 'unused variable ''foo'' (60% confidence)',
+  \     'type': 'W',
+  \     'filename': ale#path#Simplify(g:dir . '/something_else.py'),
+  \   },
+  \   {
+  \     'lnum': 12,
+  \     'text': 'unused variable ''bar'' (60% confidence)',
+  \     'type': 'W',
+  \     'filename': ale#path#Simplify(g:dir . '/second_one.py'),
+  \   },
+  \ ],
+  \ ale_linters#python#vulture#Handle(bufnr(''), [
+  \   './something_else.py:34: unused variable ''foo'' (60% confidence)',
+  \   './second_one.py:12: unused variable ''bar'' (60% confidence)',
+  \ ])
+
+
+Execute(Vulture exception should be handled):
+  call ale#test#SetFilename('something_else.py')
+  AssertEqual
+  \ [
+  \   {
+  \     'lnum': 1,
+  \     'text': 'An exception was thrown. See :ALEDetail',
+  \     'detail': join([
+  \       'Traceback (most recent call last):',
+  \       '  File "/usr/lib/python3.6/site-packages/vulture/__init__.py", line 13, in <module>',
+  \       '    from .core import stuff',
+  \       'BaddestException: Everything gone wrong',
+  \     ], "\n"),
+  \   }
+  \ ],
+  \ ale_linters#python#vulture#Handle(bufnr(''), [
+  \   'Traceback (most recent call last):',
+  \   '  File "/usr/lib/python3.6/site-packages/vulture/__init__.py", line 13, in <module>',
+  \   '    from .core import stuff',
+  \   'BaddestException: Everything gone wrong',
+  \ ])
+
+Execute(The vulture handler should handle empty output):
+  AssertEqual
+  \ [],
+  \ ale_linters#python#vulture#Handle(bufnr(''), [])